Mehran Nazir
March 19, 2011

French naval defense company, DCNS, is spearheading a
validation study on an underwater nuclear reactor design off the coast
of France, announced on January 20, 2011. Nearly 80% of France's
electricity demand is fulfilled by its nuclear energy facilities, the
highest percentage in the world. [1] Given France's proven expertise in
small- and medium-sized reactor design, construction, system
integration, and fuel R&D, France is positioning themselves to be a
leader in a technology that has potential to change the energy landscape
for many resource-constrained nations around the world.

Technology

DCNS's Flexblue technology will be at the center of
the nuclear reactor's operation. Flexblue integrates models of boilers
that have been used in submarines with nuclear propulsion. These small
nuclear boilers, along with a turbine generator, a power plant, and
auxiliary systems, will create energy to be transmitted through
submarine cables to land. The current designs of the technology (see
Figure 1) would include cylindrical hulls that measure about 100 meters
long and about 12 to 15 meters in diameter. These nuclear reactors will
be anchored anywhere between 60 to 100 meters underwater and several
kilometers off the coast. These reactors are designed to provide 50 to
250 MWe, far smaller than large nuclear reactors of today. However, this
level of energy production could suffice for anywhere between 100,000 to
1 million people. [2] Engineers intend to demonstrate a level of safety
comparable to that of today's Generation-III reactors.

DCNS will be combining its expertise in nuclear
technologies (40+ years) and its history of work in submarines (100
years) to develop this technology. DCNS is uniquely positioned in
systems and naval nuclear propulsion, and would leverage these skills to
advance this technology. DCNS will be working in conjunction with French
companies Areva, EDF, and the French Atomic Energy Commission to build
these reactors. A prototype will be built and tested by 2013, and is
targeted to be implemented in the three to four years following the
initial testing. [3]

Advantages and Risks

Proponents of this technology point out that these
submarines would be much lesser prone to terrorist attacks that
terrestrial-based nuclear reactors must face. Although attacks from the
sky are virtually eliminated, the challenge of defending these
facilities from underwater attacks remain. At the moment, plans include
a naval force to be guarding the reactor at all times.

Nuclear reactor leaks would be much more difficult
and costly to resolve for the underwater reactor. In the event of a
nuclear reactor failure, the hazards that radioactive fallout would pose
would be mitigated in water as opposed to open air. On the other hand,
having diffused throughout the water, controlling radioactive fallout in
a higher pressure region increases the technical difficulty of the
project. Operating a nuclear reactor underwater will raise the
surrounding waters by several degrees, heavily affecting the marine
biology that exists in these deep waters. This has caused major debate
between proponents of the technology and environmentalists. [4]

It is surprising that the underwater nuclear reactor
project has taken off in the aftermath of the British Petroleum disaster
that occurred this past year. The BP oil spill highlighted the
difficulties inherent in catastrophe prevention for deep water
operations. Regardless, these technologies are of enormous interest to
island nations that are resource-constrained as it is. Japan would be a
likely customer of the technology, along with Hawaii. DCNS predicts it
will sell around 200 reactors over the next twenty years [2]. There is also
a significant cost advantage to building these reactors versus the large
nuclear plants, which range in the billions of dollars. Once the
technology has been developed, estimates of these plants range in the
hundreds of millions of dollars.

In the following years, DCNS will be conducting
further research on technical and production options, market potential,
competitiveness analyses, proliferation studies, safety and security
studies.